1. Technical Field
The present application relates to an aseptic bottling or container filling plant with a clean room arrangement enclosing the aseptic bottling or container filling plant and a filter unit for filtering air entering the clean room, and a method of operation thereof. This present application also relates to a filter unit for cleaning air with at least one filter layer and a method for the sterilization of such a filter unit.
2. Background Information
Background information is for informational purposes only and does not necessarily admit that subsequently mentioned information and publications are prior art.
A beverage bottling plant for filling bottles with a liquid beverage filling material can possibly comprise a beverage filling machine with a plurality of beverage filling positions, each beverage filling position having a beverage filling device for filling bottles with liquid beverage filling material. The filling devices may have an apparatus designed to introduce a predetermined volume of liquid beverage filling material into the interior of bottles to a substantially predetermined level of liquid beverage filling material. The apparatus designed to introduce a predetermined flow of liquid beverage filling material further comprises an apparatus that is designed to terminate the filling of the beverage bottles upon the liquid beverage filling material reaching the predetermined level in bottles. There may also be provided a conveyer arrangement that is designed to move bottles, for example, from an inspecting machine to the filling machine. Upon filling, a closing station closes the filled bottles. There may further be provided a conveyer arrangement configured to transfer filled bottles from the filling machine to the closing station. Bottles may be labeled in a labeling station, the labeling station having a conveyer arrangement to receive bottles and to output bottles. The closing station and the labeling station may be connected by a corresponding conveyer arrangement.
Container handling machines include, for example, filling machines, capping machines, rinsers etc. In higher-capacity bottling plants, these machines employ a rotating construction, whereby the handling spaces that hold the containers are located on the periphery of a carousel and carry along the containers in a circulating movement during handling operations.
In some plants, the product with which a bottle or container is to be filled is a hygienically and/or microbiologically sensitive product, such as wine, beer, carbonated fruit-flavored beverages, milk products, juices, or pharmaceutical or medicinal products. Such products may be dispensed in bottles or similar containers aseptically, i.e. under clean room conditions, which bottles or containers are then closed aseptically under clean room conditions.
Some plants for aseptic bottling have a clean room or clean room area inside an enclosure which is closed off from the outside and is supplied with filtered, sterile air, and through which a conveyor line for the containers or bottles runs. In a plant of this type, inside the clean room area, a rinser, a filling machine and a capper can be provided one after another in the direction of transport. This clean room area may also be surrounded by a security area in which there are, among other things, air locks or pass-throughs for the feed of the empty containers to be filled and for the removal of the filled and capped containers. In order to maintain the desired level of cleanliness in the clean room, air filtration units may be used to remove contaminants from the air as it enters or travels through the clean room.
Filter units for cleaning air are known in a wide variety of configurations. HEPA filters are used in cases in which a high filtering capability, for example with regard to the removal of particles 0.1 μm and larger, is required and/or desired. These filters can be used to remove, restrict and/or minimize suspended substances and other particulates in the air to be filtered across a wide range of sizes, whereby there are configurations that remove 99.999% of the particulates 0.1 μm and larger from the ambient air. A filter capacity of this type is required or desired for the generation and maintenance of clean room conditions, either for chip production, in surgical theaters, or in aseptic plants for the treatment of containers, such as bottles or cans, for example, or for the filling of such containers.
In the last two applications or uses mentioned in the preceding paragraph, an aseptic atmosphere should be maintained, i.e. harmful microorganisms, spores, etc., should be removed as completely as possible from the ambient air, whereby it may be useful if such substances have already been removed from the incoming air by filtering.
Under some conditions it may be necessary or desired to sterilize or clean such filters, for example to maintain their filtering capacity or for repair or maintenance work.
Various methods are used for the sterilization of such filters, including treatment with chemical disinfectants or irradiation with UV light. Hydrogen peroxide or formaldehyde, for example, can be used for chemical disinfection.
Some sterilization methods for such filter systems have a series of disadvantages. Many chemical disinfectants, such as formaldehyde, for example, have a foul odor, are carcinogens or are otherwise harmful to health, which makes their use complicated, expensive and risky. For irradiation with UV light, complex and expensive irradiation devices are required and/or desired. When external irradiation devices are used, the filter elements must or should be removed, restricted, and/or minimized from their housing in an unsterilized condition, which can be a hazardous operation depending on the filter residues in the filters. During these operations, the filter must or should also be taken out of operation. The integration of the corresponding irradiation devices is frequently economically unacceptable.